Meldonium, the recently banned drug taken by Maria Sharapova, was widely used within her sport, the former president of the World Anti-Doping Agency has claimed. Dick Pound, who headed the recent investigation into doping in Russian athletics, said that there had been a “fairly high prevalence of use in tennis”.

But Pound suggested that tennis knew many players were taking the drug, which is known to improve endurance and reduce recovery time, before it was added to the banned list in January. “Clearly within tennis circles they were aware that a lot of the players were using it and they said there must be something to this,” he said. “So they refer it to the Wada list committee, which does the research and concludes it should be on the prohibited list, and there it is.”

However the International Tennis Federation, the governing body of tennis, denied it had officially spoken to Wada. “The monitoring of substances is undertaken by Wada, and so tennis was not aware of the prevalence of meldonium use in 2015 [or before], prior to its addition to the prohibited list,” it said in a statement.

Wada itself later released its own statement confirming that the ITF did not refer meldonium to them before its inclusion on the new list of banned substances.

Sir Craig Reedie, the president of Wada, has warned tennis that his organisation will step in if it believes that the ban Sharapova receives is too lenient. “We always have that right. In most cases we exercise that right when we think there is a really serious case to answer,” he said. “There will clearly be a great deal of interest after the last 48 hours in what the ITF do. My guess is we will watch this one very carefully.”

But a Kremlin spokesman warned that it would be wrong to use the Sharapova case to cast a shadow on Russian sport. “Of course we regret this,” a presidential spokesman, Dmiry Peskov, said. “But the situation should not be presented in such a way that it somehow casts a shadow on all Russian sports, on great achievements of our athletes. Attempts to politicise sports are destructive, unacceptable and inexcusable.”

The extent of meldonium use in sport has been revealed by research in the British Journal of Sports medicine, which suggested that up to 490 athletes may have taken it during the Baku 2015 European Games. It was detected in urine tests on 66 of the 762 samples taken at the Games, and in 15 of the 21 sports in competition.

The agent of the former 1500m world champion Abeba Aregawi said on Wednesday that the Swedish runner’s B sample has confirmed she tested positive for meldonium. Aregawi was suspended last month by her own athletics federation.